<?php
/*
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
::
::      GIFEncoder Version 3.0 by László Zsidi, http://gifs.hu
::
::      This class is a rewritten 'GifMerge.class.php' version.
::
::  Modification:
::   - Simplified and easy code,
::   - Ultra fast encoding,
::   - Built-in errors,
::   - Stable working
::
::
::      Updated at 2007. 02. 13. '00.05.AM'
::
::
::
::  Try on-line GIFBuilder Form demo based on GIFEncoder.
::
::  http://gifs.hu/phpclasses/demos/GifBuilder/
::
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
*/

Class GIFEncoder {
        var $GIF = "GIF89a";            /* GIF header 6 bytes   */
        var $VER = "GIFEncoder V3.00";  /* Encoder version              */

        var $BUF = Array ( );
        var $OFS = Array ( );
        var $SIG =  0;
        var $LOP =  0;
        var $DIS =  2;
        var $COL = -1;
        var $IMG = -1;

        var $ERR = Array (
                'ERR00'=>"Does not supported function for only one image!",
                'ERR01'=>"Source is not a GIF image!",
                'ERR02'=>"Unintelligible flag ",
                'ERR03'=>"Does not make animation from animated GIF source",
        );

        /*
        :::::::::::::::::::::::::::::::::::::::::::::::::::
        ::
        ::      GIFEncoder...
        ::
        */
        function GIFEncoder     (
                                                        $GIF_src, $GIF_dly, $GIF_lop, $GIF_dis,
                                                        $GIF_red, $GIF_grn, $GIF_blu, 
                                                        $GIF_mod, $GIF_ofs=null
                                                ) {
                if ( ! is_array ( $GIF_src ) && ! is_array ( $GIF_dly ) ) {
                        printf  ( "%s: %s", $this->VER, $this->ERR [ 'ERR00' ] );
                        exit    ( 0 );
                }
                if ( is_array ( $GIF_ofs ) && count ( $GIF_ofs ) > 1 ) {
                        $this->SIG = 1;
                        $this->OFS = $GIF_ofs;
                }
                $this->LOP = $GIF_lop === false ? false : (( $GIF_lop > -1 ) ? $GIF_lop : 0);
                $this->DIS = ( $GIF_dis > -1 ) ? ( ( $GIF_dis < 3 ) ? $GIF_dis : 3 ) : 2;
                $this->COL = ( $GIF_red > -1 && $GIF_grn > -1 && $GIF_blu > -1 ) ?
                                                ( $GIF_red | ( $GIF_grn << 8 ) | ( $GIF_blu << 16 ) ) : -1;

                for ( $i = 0; $i < count ( $GIF_src ); $i++ ) {
                        if ( strToLower ( $GIF_mod ) == "url" ) {
                                $this->BUF [ ] = fread ( fopen ( $GIF_src [ $i ], "rb" ), filesize ( $GIF_src [ $i ] ) );
                        }
                        else if ( strToLower ( $GIF_mod ) == "bin" ) {
                                $this->BUF [ ] = $GIF_src [ $i ];
                        }
                        else {
                                printf  ( "%s: %s ( %s )!", $this->VER, $this->ERR [ 'ERR02' ], $GIF_mod );
                                exit    ( 0 );
                        }
                        if ( substr ( $this->BUF [ $i ], 0, 6 ) != "GIF87a" && substr ( $this->BUF [ $i ], 0, 6 ) != "GIF89a" ) {
                                printf  ( "%s: %d %s", $this->VER, $i, $this->ERR [ 'ERR01' ] );
                                exit    ( 0 );
                        }
                        for ( $j = ( 13 + 3 * ( 2 << ( ord ( $this->BUF [ $i ] { 10 } ) & 0x07 ) ) ), $k = TRUE; $k; $j++ ) {
                                switch ( $this->BUF [ $i ] { $j } ) {
                                        case "!":
                                                if ( ( substr ( $this->BUF [ $i ], ( $j + 3 ), 8 ) ) == "NETSCAPE" ) {
                                                        printf  ( "%s: %s ( %s source )!", $this->VER, $this->ERR [ 'ERR03' ], ( $i + 1 ) );
                                                        exit    ( 0 );
                                                }
                                                break;
                                        case ";":
                                                $k = FALSE;
                                                break;
                                }
                        }
                }
                GIFEncoder::GIFAddHeader ( );
                for ( $i = 0; $i < count ( $this->BUF ); $i++ ) {
                        GIFEncoder::GIFAddFrames ( $i, $GIF_dly [ $i ] );
                }
                GIFEncoder::GIFAddFooter ( );
        }
        /*
        :::::::::::::::::::::::::::::::::::::::::::::::::::
        ::
        ::      GIFAddHeader...
        ::
        */
        function GIFAddHeader ( ) {
                $cmap = 0;

                if ( ord ( $this->BUF [ 0 ] { 10 } ) & 0x80 ) {
                        $cmap = 3 * ( 2 << ( ord ( $this->BUF [ 0 ] { 10 } ) & 0x07 ) );

                        $this->GIF .= substr ( $this->BUF [ 0 ], 6, 7           );
                        $this->GIF .= substr ( $this->BUF [ 0 ], 13, $cmap      );
                        if($this->LOP !== false)
                        {
                                $this->GIF .= "!\377\13NETSCAPE2.0\3\1" . GIFEncoder::GIFWord ( $this->LOP ) . "\0";
                        }
                }
        }
        /*
        :::::::::::::::::::::::::::::::::::::::::::::::::::
        ::
        ::      GIFAddFrames...
        ::
        */
        function GIFAddFrames ( $i, $d ) {

                $Locals_str = 13 + 3 * ( 2 << ( ord ( $this->BUF [ $i ] { 10 } ) & 0x07 ) );

                $Locals_end = strlen ( $this->BUF [ $i ] ) - $Locals_str - 1;
                $Locals_tmp = substr ( $this->BUF [ $i ], $Locals_str, $Locals_end );

                $Global_len = 2 << ( ord ( $this->BUF [ 0  ] { 10 } ) & 0x07 );
                $Locals_len = 2 << ( ord ( $this->BUF [ $i ] { 10 } ) & 0x07 );

                $Global_rgb = substr ( $this->BUF [ 0  ], 13,
                                                        3 * ( 2 << ( ord ( $this->BUF [ 0  ] { 10 } ) & 0x07 ) ) );
                $Locals_rgb = substr ( $this->BUF [ $i ], 13,
                                                        3 * ( 2 << ( ord ( $this->BUF [ $i ] { 10 } ) & 0x07 ) ) );

                $Locals_ext = "!\xF9\x04" . chr ( ( $this->DIS << 2 ) + 0 ) .
                                                chr ( ( $d >> 0 ) & 0xFF ) . chr ( ( $d >> 8 ) & 0xFF ) . "\x0\x0";

                if ( $this->COL > -1 && ord ( $this->BUF [ $i ] { 10 } ) & 0x80 ) {
                        for ( $j = 0; $j < ( 2 << ( ord ( $this->BUF [ $i ] { 10 } ) & 0x07 ) ); $j++ ) {
                                if      (
                                                ord ( $Locals_rgb { 3 * $j + 0 } ) == ( ( $this->COL >> 16 ) & 0xFF ) &&
                                                ord ( $Locals_rgb { 3 * $j + 1 } ) == ( ( $this->COL >>  8 ) & 0xFF ) &&
                                                ord ( $Locals_rgb { 3 * $j + 2 } ) == ( ( $this->COL >>  0 ) & 0xFF )
                                        ) {
                                        $Locals_ext = "!\xF9\x04" . chr ( ( $this->DIS << 2 ) + 1 ) .
                                                                        chr ( ( $d >> 0 ) & 0xFF ) . chr ( ( $d >> 8 ) & 0xFF ) . chr ( $j ) . "\x0";
                                        break;
                                }
                        }
                }
                switch ( $Locals_tmp { 0 } ) {
                        case "!":
                                $Locals_img = substr ( $Locals_tmp, 8, 10 );
                                $Locals_tmp = substr ( $Locals_tmp, 18, strlen ( $Locals_tmp ) - 18 );
                                break;
                        case ",":
                                $Locals_img = substr ( $Locals_tmp, 0, 10 );
                                $Locals_tmp = substr ( $Locals_tmp, 10, strlen ( $Locals_tmp ) - 10 );
                                break;
                }
                if ( ord ( $this->BUF [ $i ] { 10 } ) & 0x80 && $this->IMG > -1 ) {
                        if ( $Global_len == $Locals_len ) {
                                if ( GIFEncoder::GIFBlockCompare ( $Global_rgb, $Locals_rgb, $Global_len ) ) {
                                        $this->GIF .= ( $Locals_ext . $Locals_img . $Locals_tmp );
                                }
                                else {
                                        /*
                                         *
                                         * XY Padding...
                                         *
                                         */
                                        if ( $this->SIG == 1 ) {
                                                $Locals_img { 1 } = chr ( $this->OFS [ $i ] [ 0 ] & 0xFF );
                                                $Locals_img { 2 } = chr ( ( $$this->OFS [ $i ] [ 0 ] & 0xFF00 ) >> 8 );
                                                $Locals_img { 3 } = chr ( $this->OFS [ $i ] [ 1 ] & 0xFF );
                                                $Locals_img { 4 } = chr ( ( $this->OFS [ $i ] [ 1 ] & 0xFF00 ) >> 8 );
                                        }
                                        $byte  = ord ( $Locals_img { 9 } );
                                        $byte |= 0x80;
                                        $byte &= 0xF8;
                                        $byte |= ( ord ( $this->BUF [ 0 ] { 10 } ) & 0x07 );
                                        $Locals_img { 9 } = chr ( $byte );
                                        $this->GIF .= ( $Locals_ext . $Locals_img . $Locals_rgb . $Locals_tmp );
                                }
                        }
                        else {
                                /*
                                 *
                                 * XY Padding...
                                 *
                                 */
                                if ( $this->SIG == 1 ) {
                                        $Locals_img { 1 } = chr ( $this->OFS [ $i ] [ 0 ] & 0xFF );
                                        $Locals_img { 2 } = chr ( ( $$this->OFS [ $i ] [ 0 ] & 0xFF00 ) >> 8 );
                                        $Locals_img { 3 } = chr ( $this->OFS [ $i ] [ 1 ] & 0xFF );
                                        $Locals_img { 4 } = chr ( ( $this->OFS [ $i ] [ 1 ] & 0xFF00 ) >> 8 );
                                }
                                $byte  = ord ( $Locals_img { 9 } );
                                $byte |= 0x80;
                                $byte &= 0xF8;
                                $byte |= ( ord ( $this->BUF [ $i ] { 10 } ) & 0x07 );
                                $Locals_img { 9 } = chr ( $byte );
                                $this->GIF .= ( $Locals_ext . $Locals_img . $Locals_rgb . $Locals_tmp );
                        }
                }
                else {
                        $this->GIF .= ( $Locals_ext . $Locals_img . $Locals_tmp );
                }
                $this->IMG  = 1;
        }
        /*
        :::::::::::::::::::::::::::::::::::::::::::::::::::
        ::
        ::      GIFAddFooter...
        ::
        */
        function GIFAddFooter ( ) {
                $this->GIF .= ";";
        }
        /*
        :::::::::::::::::::::::::::::::::::::::::::::::::::
        ::
        ::      GIFBlockCompare...
        ::
        */
        function GIFBlockCompare ( $GlobalBlock, $LocalBlock, $Len ) {

                for ( $i = 0; $i < $Len; $i++ ) {
                        if      (
                                        $GlobalBlock { 3 * $i + 0 } != $LocalBlock { 3 * $i + 0 } ||
                                        $GlobalBlock { 3 * $i + 1 } != $LocalBlock { 3 * $i + 1 } ||
                                        $GlobalBlock { 3 * $i + 2 } != $LocalBlock { 3 * $i + 2 }
                                ) {
                                        return ( 0 );
                        }
                }

                return ( 1 );
        }
        /*
        :::::::::::::::::::::::::::::::::::::::::::::::::::
        ::
        ::      GIFWord...
        ::
        */
        function GIFWord ( $int ) {

                return ( chr ( $int & 0xFF ) . chr ( ( $int >> 8 ) & 0xFF ) );
        }
        /*
        :::::::::::::::::::::::::::::::::::::::::::::::::::
        ::
        ::      GetAnimation...
        ::
        */
        function GetAnimation ( ) {
                return ( $this->GIF );
        }
}